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A young chimpanzee named Sembe rests atop her mother Shiba in their temporary enclosure at the Taronga Zoo in Sydney, Australia. New guidelines suggest that most medical tests conducted on chimpanzees in laboratories are unnecessary.

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Aside from the small African country of Gabon, the United States is the only nation in the world that still conducts research on chimpanzees.

Last Thursday, the National Institutes of Health (NIH) announced new guidelines stating that most chimp research is not medically necessary. For any research to continue, experiments must be "necessary to advance the public's health" and have no viable alternative methods, the NIH said.

The reaction to the new guidelines has been largely celebratory: The New York Times wrote that animal welfare groups cite it as a victory in their fight against chimp research, and Theodora Capaldo, president of the New England Anti-Vivisection Society (NEAVS), which has fought for years against the practice, said, “This pivotal report is the first step toward ending all chimpanzee research in U.S. laboratories. The science guided the IOM [Institute of Medicine] to its conclusion that they are 'not necessary' – a promising outcome for chimpanzees and better science for humans.”

Some in the industry, however, see it another way. John VandeBerg, scientific director of the Texas Biomedical Research Institute, told the AP that he believes the new guidelines will have little or no impact on his facility, which runs one of the four large active chimp research programs in the country. Answers about which chimps will be released and when are vague, and the report leaves some potential loopholes.

The Institute of Medicine report specifies a couple of areas of research in which it believes the use of chimps can continue: "comparative genomics, normal and abnormal behavior, mental health, emotion, or cognition." But even within these areas, there are other scientific methods – not involving animals – that have proven to be as effective or even more effective than using chimps.

Behavioral and cognitive research: use of pediatric imaging

Behavioral and cognitive research is one of the key areas specified by the report as potentially necessary for continued chimp research. NEAVS has cited numerous studies that use pediatric imaging – and no chimpanzees – which have made advancements in understanding brain development, hyperactivity and attention deficit disorders, social reintegration after traumatic brain injury, and other brain-related topics.

According to NEAVS, which itself has a body of published scientific work, researchers can also rely exclusively on human imaging for studying source and spatial memory; cognition/brain activity; attention, perception, vision; pain, hearing, sensation; brain structure and architecture; drug effects on the brain; and other areas.

A NEAVS paper published in August adds: "Most (behavioral researchers) believe that more funding for intervention programs, qualitative clinical research, etc., using human subjects in noninvasive research and research that might in situ benefit them, is the direction behavioral research must go."

The committee that released the report last week recognized that chimps have not proved useful in HIV research, which for a long time was one of the primary areas of chimpanzee use. Opponents of chimp research – and animal testing generally – believe that someday there will be a general understanding that the same can be said for other areas of research.

"It took far too long for a consensus to be reached that chimps were not useful in HIV/AIDS research. All the while, chimps were suffering in labs and precious research dollars were being wasted, while people were waiting for progress," said Jarrod Bailey, Ph.D., a geneticist and science director for NEAVS. The organization has made the point that the longer researchers wait to find and implement alternative models, the longer it will take to establish progress in research that will improve human health in a significant way. Continuing to use a model that has limited potential is to handicap the research these animals have been suffering for in the first place.

Hepatitis C

Hepatitis C is another area that the IOM committee did not come down firmly against. Aside from humans, chimps are the only species that can be infected with the hepatitis C virus (HCV) – but infected chimps do not develop cirrhosis of the liver or liver cancer the way humans do. The report says that chimpanzees are not necessary for the development of antiviral drugs for the treatment of HCV, or for therapeutic vaccines for already-infected people, but reached no definitive conclusion on the development of a prophylactic vaccine.

Exactly half of the committee felt that chimps are not necessary for vaccine research, while the other half was uncertain about human clinical trials and whether research on chimps "would provide otherwise unattainable information on the safety of candidate vaccines." But in-vitro testing on human cell cultures and tissues has proved an effective alternative research model. Essentially, this involves testing the toxicity of substances on living cells in a petri dish: It's a faster testing method than animals are able to provide, it's more accurate because it uses culture systems of human cells, and it has already proved effective for some vaccine studies.

In a paper published in May, Bailey wrote: "It is now possible to investigate the complete HCV life-cycle, from host-cell attachment to release of progeny, immune responses to infection, the roles of host factors, identification of therapeutic targets, testing of new therapies and vaccines, and so on, in a human, and therefore completely relevant, context."

He added about HCV research generally, "While chimpanzee hepatitis C research has declined by 50-60% over the last three decades, the use of non-animal alternatives has increased 80-fold."

Bottom line: the value and ethics of chimp research

Animal groups have praised the IOM committee's conclusion that most research on chimpanzees is unnecessary. But the exceptions allowed for by the report are not excluded from what critics say about research on chimps generally.

First, there are 937 chimpanzees in the country that are kept for research. They live up to about 60 years in captivity, and are used for all kinds of research over the years. It's not like there's a group of chimps used just for hepatitis research or for HIV research. So the same animal is subject to one experiment after another – there's no such thing as a "clean sample."

Bailey has written about the scientific consequences of this practice, which "causes major psychological and physical problems for the chimps. From a scientific perspective, it causes the chimps severe stress, which results in adverse effects on the function of the immune system and increases susceptibility to many diseases and organ dysfunctions. We know that many of the chimps available for research at the various facilities in the US are very sick; if they were human, they would not be considered for participation in clinical trials for this reason."

There's also the fact that the sample size is so small. Bailey has written in a paper on this topic: "most studies involve just two to four animals, meaning that the statistical significance of the data is highly questionable, and apparent differences can often be due to inherent biological variation – a factor that cannot be addressed due to the lack of availability and the expense of acquiring more individuals. Rather, there is ample evidence that HCV drug leads progress solely on the basis of in vitro efficacy models.”

Finally – and this was a question the committee specifically said it was asked not to address – chimp research is unquestionably cruel. As Wired wrote in a September article, "cognitive studies and natural observations established beyond doubt that chimpanzees are, as befits the closest living relative of humans, deeply intelligent and emotional creatures for whom captive medical research is akin to torture."

"They are highly intelligent. They live in complex social settings, and they live for a very long time," said evolutionary anthropologist Dr. Anne Pusey, as quoted by CBS.

Yet the research has continued for decades. And while the research itself is painful and ineffective, according to sources mentioned thus far and others, it is also conducted in confined laboratory environments, adding further stress to animals that are naturally designed to live in the wild –- swinging through the trees of a forest, finding their own food, building their own nests for sleeping at night.

The report's second criterion is that all experiments use "techniques that are minimally invasive, and in a manner that minimizes pain and distress." Minimally invasive is likely a subjective term and defined differently by researchers and opponents of chimp research, including Jane Goodall, who said about the conditions of one laboratory in particular: “In no lab I have visited have I seen so many chimpanzees exhibit such intense fear. The screaming I heard when chimpanzees were being forced to move toward the dreaded needle in their squeeze cages was, for me, absolutely horrifying.”

It is also virtually impossible to minimize the distress in a laboratory environment. In the August paper for NEAVS, Capaldo and Bailey also wrote: "All chimpanzees in a laboratory are, inherently and unavoidably, stressed by that environment, which has significant consequences for gene expression and related biology. This affects and confounds all data produced, over and above any inter-species differences that are present."

While the report makes clear that most research on chimpanzees should now be viewed by the NIH as unnecessary, it remains to be seen how much the guidelines are up for interpretation.

"If the criteria aren’t scrupulously applied... then there is a risk that little change will be effected," Bailey said in an email. "Applying the criteria stringently is imperative, if the IOM inquiry and report is to have been worthwhile."